Prior art fixture can be implanted into a piece of ammunition including a vector, such as a missile. Indeed, it is known that some ammunition parts must be separated from each other upon firing and during the flight trajectory. That is in particular the case between the shell base or the lower part of the piece of ammunition and the acceleration and rocking system of the missile being attached in particular between them by such specific fixture bearing electrical connectors and separable mechanical attachment systems, and arranged within an internal ring space provided between the shell base and the acceleration system.
The electrical connectors serve to establish the communication (information transfer) between the acceleration and rocking system of the missile and the firing facility and must be consequently perfectly connected, and then separated by the mechanical attachment systems according to the orders being transmitted.
For example, a known fixture for assembling two cylindrical components with a common longitudinal axis, usually comprises:                two support plates respectively inserted facing one another on the components substantially on the periphery of the latter;        at least three electrical connectors each in two parts, mounted in parallel between them and aligned in a circular arc with respect to said longitudinal axis on said support plates, each of them bearing the corresponding parts of the connectors, and        between the three electrical connectors, parallel to the latter, two separable mechanical attachment systems fixedly connecting said support plates by locking said parts of the connectors.        
The grouping of the three electrical connectors on a same single fixture, moreover aligned on a common circular arc with the attachment systems arranged symmetrically with the connectors, on said circular arc, leads to occupy a minimum volume between the components with in addition an important weight gain and a lesser performance complexity, in comparison with a design with three distinct fixtures for the respective connectors being distributed by 120° with each other and provided then with two attachment systems symmetrically arranged for each electrical connector.
Although giving satisfactory results, such compact fixture with three electrical connectors and two mechanical attachment systems can present some disadvantages, in particular, upon the positioning of the electrical connections, when clamping the attachment systems on the support plates on which the respective parts of the connectors are fastened and which are coming closer to each other.
Indeed, as both electrical end connectors being identical between them are dimensionally bigger than the central electrical connector, the stiffness to be overcome so as to ensure the total connection between the two parts of these end connectors is then well higher than the one of the central connector. Such stiffness being determined by connector manufacturers depending on various parameters (current, environment, size, etc.), is given by a rubber element or carpet arranged between the two parts and which has to be pressed to ensure the sealing of the electrical connection of the connectors. So, as this stiffness is bigger at the level of the end connectors and that the connecting systems are on the same circular arc as the connectors, upon the positioning of the fixture during the clamping of the attachment systems while crushing the sealing elements, the axial efforts exerted by the systems tend to rock the mobile support plate with respect to the other support plate so that the so obtained fixture is not perfectly correct, which is not desirable in the application in question.